Binder Rings vs. ISO 838 (2-Hole)
Comparing 2 standards across 13 specifications. 13 key differences identified.
Binder Ring Mechanisms (manufactured in Round Ring, Straight D-Ring, and Slanted Angle D-Ring profiles) are mechanical document holding spines sized by internal ring diameter from 0.5 inches (13 mm / 100 sheets) up to 4.0 inches (102 mm / 900 sheets). D-rings hold up to 25% more pages than round rings of the same nominal size by stacking pages against a flat vertical spine.
ISO 838 (DIN 821) is the international standard for 2-hole paper punching, specifying two circular holes spaced exactly 80.0 mm ± 0.5 mm apart with a diameter of 6.0 mm ± 0.5 mm, positioned 12.0 mm ± 1.0 mm from the binding edge of the sheet. It is the universal standard for ring binders and lever arch files across Europe, Asia, Africa, and Latin America.
Specification Comparison Table
13 Parameters| Parameter / Spec | ||
|---|---|---|
|
0.5-inch Ring Capacity (13 mm)
|
Approx. 100 to 125 sheets (20 lb bond paper) | — |
|
1.0-inch Ring Capacity (25 mm)
|
Round Ring: 175 sheets | D-Ring: 220 to 250 sheets (+25% capacity) | — |
|
1.5-inch Ring Capacity (38 mm)
|
Round Ring: 275 sheets | D-Ring: 350 to 400 sheets | — |
|
2.0-inch Ring Capacity (51 mm)
|
Round Ring: 375 sheets | D-Ring: 480 to 540 sheets | — |
|
3.0-inch Ring Capacity (76 mm)
|
Round Ring: 450 sheets | D-Ring: 650 to 720 sheets | — |
|
4.0-inch Ring Capacity (102 mm)
|
D-Ring / Angle D-Ring only: 850 to 950 sheets (heavy-duty locking booster) | — |
|
Mounting Location
|
Round rings mount to spine; D-rings mount to back cover (enabling flat page opening) | — |
|
Center-to-Center Hole Spacing
|
— | 80.0 ± 0.5 mm (3.15 in) |
|
Hole Diameter
|
— | 6.0 ± 0.5 mm (0.24 in) |
|
Edge Distance to Hole Center
|
— | 12.0 ± 1.0 mm (0.47 in) |
|
Centering Standard
|
— | Holes are centered symmetrically along the paper's long edge (A4) or short edge (A5) |
|
Target Paper Pairing
|
— | ISO 216 A4 (210 × 297 mm) and A5 (148 × 210 mm) |
|
Binder Compatibility
|
— | 2-ring binders, European lever arch files (Leitz Ordner, Esselte, Rexel) |